This invention relates to controlling flow of gas in a compressed gas system, and more particularly to a check valve for use in the delivery of air under pressure from an air compressor to a storage tank holding the air under pressure.
Check valves are in widespread use for permitting pressurized gas to flow through a passage in one direction and preventing flow in the reverse direction. Most check valves have a movable poppet which is urged by a spring to engage a valve seat, thereby closing the valve. When force on the poppet due to air pressure exceeds the force of the spring, the poppet moves away from the seat, thereby opening the valve.
One application is at a fitting on the storage tank, where a check valve receives a flow of air from a compressor for delivery to the tank, and then retains air in the tank when the compressor shuts off. That valve is exposed to a severe environment typical for a compressor discharge, including large air pressure fluctuations and turbulent flow. Consequently, the poppet and other parts of the valve are subject to substantial vibrations which can result in noise, damage, and/or failure. Some valves of the prior art include a guide mounted inside the valve for guiding movement of the poppet to prevent damage. Unfortunately, these guides are frequently located at a position within the valve where installation and replacement of a guide is difficult, or they are flexible in construction or otherwise ill-suited for the severe environment. Moreover, some guides or springs have configurations which obstruct a significant portion of the available flow area of the passage, thereby degrading air pressure as it flows through the valve and potentially causing additional vibration or failure.